Plant crude extracts with potential broad spectrum activity

Bacterial infections continously create clinical problems and therapeutic dilemma to many. And a rapidly growing problem concerning baterial infections nowadays is the development of antibiotic resistance among pathogenic microorganisms. Thus, the availability of antibiotics is gradually becoming limited. Although there are pharmaceutical companies which have developed a succession of new more potent, broad-spectrum antibiotics, but this brought remedy to some due to the stagerring cost of this drugs, with this, the researchers believe that the discovery of alternative medicinal plants that could inhibit the growth of pathogenic bacteria and at the same time affordable can offer the solution. This study screened the potential antibacterial effect of some locally available plants namely amorseco (Andropogon aciculatuz Retz), cashew (Anacardium occidentale Linn), guava (Psidium guajava Linn), eucalyptus (Eucalyptus tereticornis Sm), and rambutan (Nephelium lappaceum Linn). Crude ethanol extract of each of these plants was prepared. Potential antibacterial effect was screened by Kirby-Bauber disk diffussion method, using both the Gram positive S. aureus ATCC 25923 and the Gram negative P. aeruginosa ATCC 27853 and E. coli ATCC 25922. These bacteria have known susceptibility to antibiotics. Also included was a multi-drug resistant strain of K. pneumoniae (ATCC 700603), to further screen the ability of the extracts to inhibit multi-drug resistant bacteria. Bioassay screening of the different plant samples showed that crude extracts from the leaves of eucalyptus, guava, as well as seeds of cashew have good quality against Gram positive bacteria. Guava and cashew also showed satisfactory result with Gram negative bacteria, as well as with the resistant K-pneumoniae. It was further determined that the crude extracts of guava and cashew are "broad spectrum" in activity, suggesting that these plants may be used to give remedy to a wide range of bacterial infections.